A shoelace fits an upper to the foot. The upper fitting the foot supports the foot.
However, during dorsal flexion of the MP joint, the foot shape changes, and therefore the foot circumference also changes. When shoes are worn over a long period of time, the foot circumference increases in many cases. In such a case, the foot inside a shoe will be compressed by the upper. Moreover, the shoe and the foot are likely to slip against each other during action.    [First Patent Document] Japanese Laid-Open Patent Publication No. 2006-258 (abstract)    [Second Patent Document] Japanese Laid-Open Patent Publication No. 11-18803 (abstract)    [Third Patent Document] Japanese Utility Model Publication for Opposition No. 33-5240 (FIG. 1)    [Fourth Patent Document] Japanese Utility Model Publication for Opposition No. 5-9843 (FIG. 3)    [Fifth Patent Document] EPO 329,392 A2 (abstract)    [Sixth Patent Document] Japanese Laid-Open Patent Publication No. 4-44701 (page 2, upper right col.)    [Seventh Patent Document] WO 2004/93587 A1, US 2006/0162190 A1 (abstract)
With a shoe of the first document, non-stretchable belts are fixed to the inner side of a stretchable upper, and the non-stretchable belts prevent the upper from stretching. In the shoe of the first document, an eyelet (loop) is provided at the tip of each non-stretchable belt, and therefore the eyelet will not move in the foot circumference direction in the shoe (while the shoe is worn).
The belts are continuous with each other in the front-back direction, with the tips of the belts attached to the stretchable member of the upper, and therefore the belts are prevented from being displaced freely.
A shoe of the second document has a size that is variable in the foot length direction. In order for the size to be variable in the foot length direction, this shoe includes, provided in the middle foot portion, a flexible fabric portion that is stretchable in the front-back direction of the upper. The flexible fabric portion does not stretch in the circumference direction. Therefore, since the eyelets provided in the flexible fabric portion do not move in the circumference direction, the foot will be compressed while the shoe is worn.
A shoe of the third document includes a wide stretchable piece on each side surface of the front foot portion. The wide stretchable piece may feel less compressive to the foot. However, the wide stretchable piece will not be able to support the side surface of the foot.
Since the ornamental eyelets are continuous with each other in the front-back direction, the eyelets will not move in the front-back direction. Therefore, the eyelets are prevented from moving freely.
The eyelet members of the fourth document are formed by a resin whose Shore hardness is 90 to 100. A resin whose Shore hardness is 90 to 100 will hardly stretch.
With a shoe of the fifth document, the rear foot portion is supported by a non-stretching supporting stirrup.
A shoe of the sixth document includes a pair of side panels (fastening bands) sandwiched between the inner skin and the outer skin of the upper. The side panels may be formed by a rubber sheet or a stretchable fabric, and each includes three eyelets. The aim of the shoe of the sixth document is that the side panel stretches and shrinks in the circumference direction depending on the magnitude of the foot circumference (circumferential length) of the person.
However, with the invention of the sixth document, the object is that the side panels connected together with shoelaces do not move on the upper skin in the front-back direction and reliably fasten a predetermined position of the instep of the foot, as stated on (page 1, right col. or) page 2, lower right col. of the publication, and the side panels are wide. Therefore, eyelets formed in the side panels are not at all intended to move in the front-back direction of the foot, and it is believed that they do not substantially move so.
With the invention of the sixth document, the side panels formed by a rubber sheet or a stretchable fabric cover large areas of the side surfaces of the foot, and even cover areas posterior to the metatarsal bones. This will detract from the upper's function of holding or supporting the foot of the wearer.
With a shoe of the seventh document, eyelets formed by loops are provided in the vicinity of stretchable portions. Although it may appear from FIG. 5 of the seventh document that the loops are connected to the stretchable portions, the loops are provided on hard portions of the upper as can be seen from FIGS. 3 to 6 of the publication.
Therefore, the eyelets formed by loops shown in the publication cannot move in the circumference direction.